1. Field of the Invention
The present invention relates to a waterwheel apparatus, and more particularly to a high efficiency waterwheel apparatus having track-type blades and a track-type blade set thereof.
2. Description of the Related Art
In general points of view, it is considered that only a high-speed water flow is worthy of development, and therefore, research and development on a waterwheel apparatus is carried out for the high-speed water flow (over 2.75 m/s), for example, Taiwan (R.O.C.) patent publication No. 200835852 entitled “WIND-FORCE OR WATER-FORCE POWER GENERATION DEVICE” and Taiwan (R.O.C.) patent publication No. 200844325 entitled “A METHOD AND APPARATUS FOR OPERATING AN UNDERWATER POWER PLANT” disclose the related invention. At present, the location of the high-speed water flow (over 2.75 m/s) around the world is few, or is not suitable for commercial use as the water flow is far away from the land; while a low-speed water flow (0.5 m/s to 2 m/s, for example, an ocean current in 30 m to 50 m water depth) is widely distributed, for example, the fastest flow rate of Pacific Kuroshio in the east of Taiwan is about 1.4 m/s, which falls in the category of the low-speed water flow. However, it is generally considered that the low-speed water flow is not worthy of development, so no one is willing to develop a high efficiency waterwheel apparatus applicable to the low-speed water flow. It is a great pity that such water flow energy is gratuitously wasted in the case of energy shortage and emphasis on environmentally-friendly and renewable energy at present.
A power unit of the waterwheel apparatus for water flow power generation has two types of technologies: a propeller type (for example, Taiwan (R.O.C.) patent publication No. 200817238 entitled “FLUID ENERGY CONVERTER”, Taiwan (R.O.C.) patent publication No. 200930895 entitled “WATER FLOW POWER GENERATION DEVICE”, and Taiwan (R.O.C.) patent publication No. 201009188 entitled “WATER FORCE POWER GENERATION DEVICE”) and a rotary blade type (for example, Taiwan (R.O.C.) patent publication No. 201007009 entitled “WATER WHEEL IMPELLER TYPE POWER GENERATOR”, Taiwan (R.O.C.) patent publication No. 200408767 entitled “WATER LEVEL KINETIC ENERGY GENERATION MECHANISM”, and Taiwan (R.O.C.) patent No. 495586 entitled “MARINE ENERGY DRIVEN PUMP (SECOND CASE)”). When the propeller-type power unit is applied to the water flow, since a viscosity coefficient of the water is much greater than that of the air, a high frictional resistance is formed, so a sufficient rotation speed or torque is not easily obtained, and therefore, such a power unit is not a desirable water flow power generation unit. By contrast, the rotary-blade-type power unit is a better water flow power generation unit. However, since the blades of the conventional rotary-blade-type waterwheel apparatus are fixed, when the waterwheel rotates to a counterflow side, a resistance is formed, which reduces the application efficiency of the water flow energy, and even causes the waterwheel to stop rotating. Therefore, many problems remain to be solved.
For example, FIG. 1 is a schematic view of a conventional rotary-blade-type waterwheel apparatus disclosed in Taiwan (R.O.C.) patent No. 495586 entitled “MARINE ENERGY DRIVEN PUMP (SECOND CASE)”. The waterwheel apparatus 1 includes a rotating disk 11 and a plurality of blades 12. The blades 12 are fixedly disposed on the rotating disk 11, and when the blades 12 are driven by a water flow 14, the rotating disk 11 also rotates accordingly, thus driving an axle center of a power generator (not shown) to rotate and generate power. When the waterwheel apparatus 1 is placed in the water flow 14, the blades 12 in a lower area C directly face the water flow 14 by their front surfaces, and bear the maximum thrust, which drives the waterwheel apparatus to rotate counterclockwise. However, as the blades 12 are fixed to the rotating disk 11, it is the back surface of the blades 12 in an upper area D that faces the water flow 14, which bear a thrust having the same magnitude as the thrust applied on the blade 12 in the area C but in a opposite direction. Therefore, the rotating forces applied to the rotating disk 11 in the two areas are counteracted, so that the waterwheel apparatus 1 has a low efficiency and is merely applicable to a high-speed water flow.
Further, in a conventional waterwheel apparatus, a planetary gearbox device is used to change angles of blades. FIG. 2 is a schematic view of Taiwan (R.O.C.) patent publication No. 200940822 entitled “WATERWHEEL APPARATUS HAVING SOLAR-PLANETARY TYPE BLADES”. Referring to FIG. 2, when the blades of the waterwheel apparatus revolve around a central axis, the blades rotate at the same time. When the blades revolve to a counterflow position, they already rotate to a direction parallel to the water flow, which reduces the resistance. Therefore, an effective area of the blades is much larger than an ineffective area, and the power generation efficiency is improved accordingly. In this prior art, a transmission mechanism is mainly used to change the angles of multiple blades, and maintain the same angle difference between the blades. It indicates that the transmission mechanism may be a planetary gearbox in one embodiment. However, the conventional transmission mechanism is a closed planetary gearbox, and lubricating oil needs to be added into the planetary gearbox. When the waterwheel apparatus is completely placed in water during operation, a sealing member in an axle rotating portion becomes rather important. If the lubricating oil inside the planetary gearbox leaks due to a poor sealing effect, the marine environment may be polluted. Therefore, in order to maintain the sealing effect of the sealing member, the maintenance cost of such a waterwheel apparatus is dramatically increased.
In addition, the undersea operation mechanism such as the conventional waterwheel apparatus mostly adopts antifouling coating to decelerate the growth speed of the marine organism, but the effect is undesirable, and it still needs to scrape the marine organism accretion and re-coat the antifouling coating regularly, so that the consumed labor and materials also raise the cost for maintaining the waterwheel apparatus.
The components for constructing the planetary gearbox are numerous, and at least five gear sets with different functions and applications are used in the prior art. Each of the gear sets is respectively configured with elements such as a pivot, a bearing, and a sealing member. In order to keep a valid blade angle, the same angle difference between the multiple blades needs to be maintained, and therefore, a large number of various spares are need to be prepared for replacement during maintenance. However, when the spare such as a gear is replaced, the complex assembly structure causes the replacement to be rather troublesome and error-prone, and the maintenance work is delayed accordingly.
Moreover, the conventional transmission mechanism is limited to the case that the gear is a transmission device, and the rotation of the multiple blades is set at a fixed angular velocity in order to maintain the same angle difference between the blades. Therefore, for the waterwheel design, an optimal scheme can only be made by using a collector mask and change of the shape of the blades, so the obtained effect is also limited.
Therefore, the waterwheel apparatus used for water flow power generation still has many technical problems to be solved.